The present invention relates to a switch checking system and more particularly to a switch checking system for examining whether or not a switch to be operated through the operation of a copying apparatus is normally operated in a copying apparatus whose operation is controlled by such a program controlling apparatus such as a microcomputer.
The control of the operation of a copying apparatus is generally performed by a microswitch which turns on and off through the operation of the copying apparatus, a lead switch or a switch for a photointerrupter or the like. Since this type of switching operation has important influences upon the copying operation, it is necessary to check the performance of the respective switching operations during the assembly of the machines, the repairing and inspecting thereof or the like.
Thus, the switching functions of the individual switches were checked with appliances such as tester (circuit tester), etc., or the machine was actually operated to check whether or not the machine was controlled in accordance with a given program.
However, to check the switching operation of the individual switches with appliances such as tester, etc., not only the wiring, but also wirings or connectors located between the switches and the connecting apparatus were required to be checked to find the failures. Accordingly, the checking operation of the switches required more time. Also, to check the switches after the assembly of the machines, the components with the switches built-in therein were required to be dismantled or the cover of the machine was required to be removed to examine the switch.
Also, to check whether or not the machine is controlled in accordance with a given program through the actual operation of the machine, the checking operation could be performed as to whether or not the individual switches were normally operated through the actual operation of the copying apparatus after the confirmation of the automatic operation of the completed copying apparatus in accordance with a given sequence. However, the checking operation could not be performed as to whether or not the individual switches were normally operated to trace the causes in a case where the given operation could not be performed at a stage of the manufacturing test of the copying apparatus or at a testing stage of the automatic operation.
In recent years, the accumulation of the electronic circuits has been progressed so that microcomputers provided with stored program functions can be inexpensively used in great quantities. Even middle-sized PG,4 or small-sized copying machines employ microcomputers for sequence controlling operation.
The copying apparatuses to be controlled by this type of program controlling apparatuses were provided, in the program, with routines for operating a copying apparatus for testing operations in accordance with various modes or routines for checking electrical conduction failures or wire disconnections in each component of the machine, but were not provided with a program routine for checking the switching condition.
Accordingly, even in a copying apparatus having a failure detecting function through the use of a program controlling apparatus, the above-described programs concerning the switch checking operation are not removed at all.